This invention relates to heat exchangers and more particularly to improved fireplace type heating units.
In the past tube type heat exchangers have been used in fireplaces. These units today generally take the form of a front manifold with heating pipes which act as a grate for the fire logs thereon, curving up and going back out into the room in generally a U-shaped configuration. A blower is quite often attached to the front of the manifold to force the air through the heat exchanger rather than depending on convection currents.
Also the use of glass doors has become relatively common. These generally take the form of two pairs of folding doors for a total of four glass panels with a relatively flimsy frame thereabout and a damper at the bottom to allow air from inside the house to feed the fire for combustion purposes when the doors are closed.
With the cost of fossil fuel going up and home owners becoming more aware of energy conservation, heat exchangers of the type described are being used in conjunction with separate glass doors which are in most cases purchased from different suppliers.
The broad concept in and of itself of introducing air from the exterior of a building into the firebox portion of a fireplace to effectuate combustion and either reduce or eliminate warm interior air from being sucked up the chimney during the burning process of the fire is known. The detailed construction of these air inlet systems, however, are usually of relatively exotic design and are at best costly to install. Also the air control of such air feed systems leaves much to be desired.